Studying the mechanics of Bauhinia seeds pod opening we developed a geometric-mechanical model for elastic ribbons with spontaneous saddle-like curvature. When the width of such ribbons grows beyond a critical value, the ribbons undergo a twist-to-helical transition. Experimental study of this transition, using synthetic sheets and pods valves shows excellent agreement with theoretical predictions.
I will show the geometrical equivalence between the seed pod and some self assembled supramolecular structures of chiral molecules. Based on this equivalence we derive several predictions regarding shape selection and shape evolution in such macromolecules.
erans@mail.huji.ac.il
